Thursday 8 September 2011 06.14 EDT
First published on Thursday 8 September 2011 06.14 EDT

Professor Chris Lavy, an orthopaedic surgeon who spent years working in Africa, gives a vivid example of inappropriate medical technology for the developing world.

One of the newest hospitals in sub-Saharan Africa, he points out, was built with infrared sensors to turn the taps on in the operating theatres. "Wonderful idea, but is it really appropriate in a country where there are no other infrared controlled taps and no engineer to fix them," he asks rhetorically. "Within a year most of them had failed, some in the off position and some in the on position."

It is a familiar problem. A well-meaning donor gives a shiny new piece of equipment to a poor country only for it to gather dust. Parts that are expensive and difficult to replace, the need for a constant electricity supply, a lack of trained operators, unsuitability to rough terrain are all factors preventing the use of these devices in the developing world.

"Factors contributing to this are: lack of needs assessment, appropriate design, robust infrastructure, spare parts when devices break down, consumables and a lack of information for procurement and maintenance, as well as trained healthcare staff," says the WHO. "These issues are part of a broader problem in many countries: the lack of a medical device management system."

They include a nipple shield for breastfeeding HIV-positive mothers, which can block transmission of the virus to their babies; an eRanger ambulance – a motorbike sidecar stretcher that can handle rough terrain far better than a four-wheeled ambulance and is much cheaper; and a stethoscope that can attach to a mobile phone, allowing doctors to monitor hard-to-reach patients remotely.

The heart-rate monitoring device is particularly ingenious as the microphone on a mobile phone is used as a stethoscope to analyse and record heart sounds. This means a patient's condition can be analysed by a doctor hundreds of miles away. The device specifically targets tuberculosis pericarditis, which affects around 10% of all TB patients and has an unusually high mortality rate (40%). It would be particularly useful for remote rural communities where access to qualified doctors for routine check-ups can be difficult.

The onset of symptoms is insidious and sufferers in developing countries not being able to reach the clinic before it is too late accounts for the high death rate. Being able to pick up the early warning signs by monitoring the heart could therefore be crucial. As half of Africa's 1 billion population have mobile phones, the mobile stethoscope could be a simple and cheap solution to the problem.

The idea came from a conversation between Professor Bongani Mayosi, at the University of Cape Town, and Thomas Brennan, a post-doctoral researcher at the Oxford department of engineering science, about how to bring down tuberculosis pericarditis mortality rates in a low-cost way.

"All you need are a mobile phone, a hands-free kit and an egg cup that you put against your chest," said Brennan. "Then you can send the recording by SMS over the phone. Tests have shown that the results are as good as when you use a £400 [$640] 3M Littmann stethoscope, and a clinical study is being done in October awaiting approval."

Even more low-tech is a donkey ambulance for remote villages in Afghanistan, developed by HealthProm, a British NGO. This consists of a specially designed seat that can be attached to a donkey. It provides cheap emergency transport using the donkeys that locals already use to travel through mountainous regions.

Another device, called Hearware, is a solar-powered hearing aid that uses bone conduction to send vibrations to the working cochlea, bypassing the need for expensive batteries and treating the type of hearing loss most prevalent in the developing world. The internal battery charges from four hours of sunlight and lasts for three days. It was developed by Andrew Carr, at Glasgow University, five years ago.

"For years, many hospitals around the world have been forced to rely on inappropriate hand-me-downs from richer countries, but what use is an ambulance to a village with no paved roads, or a dialysis machine to a clinic with no mains electricity," asks Patrick Finlay, medical division chairman at IMechE. "Simple, inexpensive technologies engineered for use in the developing world have the potential to save thousands of lives. It's now up to the engineering and development communities to get these technologies out of the workshop and into the world's poorest countries."